Existing micro-reagent delivery systems require external actuators such as pneumatic pumps, syringe pumps, thermo-pneumatic or micro-centrifuge devices for efficient operation. While these approaches for fluid actuation are effective they appreciably increase instrumentation foot print, mass and often require planar and stable surfaces to operate effectively. Furthermore, their energy consumption requirements are not conducive to prolonged battery life and as such operate using mains power. As a consequence, these micro-reagent delivery systems are typically not suitable for mobile or handheld chemical diagnostic devices. Examples of systems employing these methods are many including Gyros (www.gyros.com), Achiralabs (www.achiralabs.com) etc.
United States Patent Application No: US2005/0180891 (FIG. 12-14) discloses a miniaturised fluid delivery and analysis system comprising an upper substrate and a lower substrate separated by a flexible intermediate layer, an open reservoir, a reaction chamber, a pump and a hole formed in the second substrate to allow for pumping of fluid between the reservoir and reaction chamber. The system is designed to connect with an external reservoir of reagent fluid prior to use, and as such is designed as an open system without any barrier between the open reservoir and the reaction chamber. This means that reagents cannot be stored on board the device thus restricting “out of laboratory” applications.
It is an object of the invention to overcome at least one of the above-referenced problems.